Summary At approximately 0830 eastern standard time (EST)(1), the pilot and one passenger departed from the ice surface of the St. Marys River, near the Sault Ste. Marie, Ontario, sea plane base (Partridge Point), in a ski-equipped Aeronca 11CC Super Chief aircraft. The purpose of the trip was to go ice fishing on Buck Lake, and they planned to return at about 1800. When the aircraft had not returned and was overdue, a search was initiated at 2035. The visual search was hampered by darkness; however, the next morning, a search aircraft reported a hole in the ice on the St. Mary's river just west of Bells Point. An inspection of this hole revealed the submerged aircraft in about 12 feet of water. The aircraft was situated on the bottom of the river in an upright position, facing west. Both the pilot and the passenger were found outside of the submerged aircraft and under the ice surface. Both of the occupants had succumbed to hypothermia and drowning. Ce rapport est galement disponible en franais. Other Factual Information Witnesses at Buck Lake confirmed that the aircraft had arrived and landed at about 0920 EST. The pilot and the passenger talked to two other ice fishermen who were at the lake and then set their ice fishing lines in the same vicinity. The pilot and the passenger were still fishing on Buck Lake at 1400 EST when the other fishermen departed the area. The day after the accident, one of the fishermen indicated that the pilot had told him that there had been some unspecified problem with the tail of the aircraft. The exact nature of the apparent problem was not known. The aircraft was examined by Ontario Provincial Police divers with an underwater video camera. It was sitting upright on the bottom of the river, undamaged except for a minor dent in the engine cowl and a minor bend in the right wing fillet fairing. The propeller was undamaged. Both seat-belts were found undone and both doors were open. The engine throttle was found pulled in the idle position and the carburettor heat control was found pulled fully back in the hot position. The magneto switch was found in the both position. The ice in the vicinity of the sunken aircraft was estimated to be one to two inches thick around the hole and the water had a mild current. Such a thin layer of ice would not have supported the weight of either the pilot or the passenger. Thicker regions of ice were noted in other areas of the river. The water temperature was reported to be about one degree Celsius. The pilot was certified and qualified for the flight in accordance with existing regulations. Both occupants displayed minor injuries, consistent with no or minimal impact forces. No potentially incapacitating medical conditions were evident in the pilot at the post mortem. Both the pilot and the passenger were wearing appropriate winter clothing for their fishing activity.